Add initial prototype.

2022-07-31 17:34:54 +10:00
commit 54a53b2ac0
1421 changed files with 358874 additions and 0 deletions
--- a/3-mid/opengl/private/gid/gid-decoding_jpg.ads
+++ b/3-mid/opengl/private/gid/gid-decoding_jpg.ads
@@ -0,0 +1,89 @@
+private package GID.Decoding_JPG is
+
+  use JPEG_defs;
+
+  type JPEG_marker is
+  (
+    SOI      , --  Start Of Image
+    --
+    SOF_0    , --  Start Of Frame - Baseline DCT
+    SOF_1    , --  Extended sequential DCT
+    SOF_2    , --  Progressive DCT
+    SOF_3    , --  Lossless (sequential)
+    SOF_5    , --  Differential sequential DCT
+    SOF_6    , --  Differential progressive DCT
+    SOF_7    , --  Differential lossless (sequential)
+    SOF_8    , --  Reserved for JPEG extensions
+    SOF_9    , --  Extended sequential DCT
+    SOF_10   , --  Progressive DCT
+    SOF_11   , --  Lossless (sequential)
+    SOF_13   , --  Differential sequential DCT
+    SOF_14   , --  Differential progressive DCT
+    SOF_15   , --  Differential lossless (sequential)
+    --
+    DHT      , --  Define Huffman Table
+    DAC      , --  Define Arithmetic Coding
+    DQT      , --  Define Quantization Table
+    DRI      , --  Define Restart Interval
+    --
+    APP_0    , --  JFIF - JFIF JPEG image - AVI1 - Motion JPEG (MJPG)
+    APP_1    , --  EXIF Metadata, TIFF IFD format, JPEG Thumbnail (160x120)
+    APP_2    , --  ICC color profile, FlashPix
+    APP_3    ,
+    APP_4    ,
+    APP_5    ,
+    APP_6    ,
+    APP_7    ,
+    APP_8    ,
+    APP_9    ,
+    APP_10   ,
+    APP_11   ,
+    APP_12   , --  Picture Info
+    APP_13   , --  Photoshop Save As: IRB, 8BIM, IPTC
+    APP_14   , --  Copyright Entries
+    --
+    COM      , --  Comments
+    SOS      , --  Start of Scan
+    EOI        --  End of Image
+  );
+
+  YCbCr_set : constant Compo_set:= (Y|Cb|Cr => True, others => False);
+  Y_Grey_set: constant Compo_set:= (Y => True, others => False);
+  CMYK_set  : constant Compo_set:= (Y|Cb|Cr|I => True, others => False);
+
+  type Segment_head is record
+    length : U16;
+    kind   : JPEG_marker;
+  end record;
+
+  procedure Read(image: in out Image_descriptor; sh: out Segment_head);
+
+  -- SOF - Start Of Frame (the real header)
+  procedure Read_SOF(image: in out Image_descriptor; sh: Segment_head);
+
+  procedure Read_DHT(image: in out Image_descriptor; data_length: Natural);
+  procedure Read_DQT(image: in out Image_descriptor; data_length: Natural);
+  procedure Read_DRI(image: in out Image_descriptor);
+
+  procedure Read_EXIF(image: in out Image_descriptor; data_length: Natural);
+
+  --------------------
+  -- Image decoding --
+  --------------------
+
+  generic
+    type Primary_color_range is mod <>;
+    with procedure Set_X_Y (x, y: Natural);
+    with procedure Put_Pixel (
+      red, green, blue : Primary_color_range;
+      alpha            : Primary_color_range
+    );
+    with procedure Feedback (percents: Natural);
+    -- mode: Display_mode; -- nice -> progressive nicely displayed
+  --
+  procedure Load (
+    image     : in out Image_descriptor;
+    next_frame:    out Ada.Calendar.Day_Duration
+  );
+
+end GID.Decoding_JPG;